Mainframe Tips, Tricks And Tutorials: February 2012

Friday, February 17, 2012

Bypassing Label processing for tape datasets

Bypass Label Processing (BLP) is a method of accessing tapes or cartridges. Use of BLP is usually restricted, requiring RACF authority, because great care is required.

BLP is often used if the dataset name or volume serial is not known, such as when recieving a tape from an external organization.

To specify that you want to read a tape or cartridge using BLP, you should specify BLP in the LABEL parameter of the DD statement.

LABEL=(2,BLP) specifies you want to read the second file on the tape/cartridge. Note that any Headers and Trailers on the tape/cartridge are treated as being files.

Any tape format can be read using BLP, from Standard Label to No Label.

To calculate the file number use the following formula:

x=3y - 1

where x is the number to be used with BLP (ie LABEL=(x,BLP) ), and y is the number of the file (excluding headers, trailers,etc) that you want to access (ie the file number you would use for standard labels (SL) ), so if you want to access the first file on a tape (with headers & trailers) x would be (3*1) - 1 , So you would code LABEL=(2,BLP). The second file would be accessed using LABEL=(5,BLP). (Remember there will be headers and trailers for each file).

To access the Header record code LABEL=(,BLP)

No dataset name or volume serial number validation is done with BLP so your DSN name and VOL=SER can be set to any value.

When you run your job with BLP a message will appear on the Operator Console requesting the Volume Serial Number. Once the VOLSER is entered at the console the job step will start and the tape is processed.

Avoiding tape mount in IEFBR14 step for tape datasets

Let us assume that MY.TAPE.DSN is in tape. The below IEFBR14 step is trying to delete the file. To delete the file, first it mounts the tape volume which has the dataset and then it deletes the dataset.

//JS0050 EXEC PGM=IEFBR14
//DEL01 DD DSN=MY.TAPE.DSN,
// DISP=(MOD,DELETE,DELETE)

To avoid such unnecessary tape mount, we can use IDCAMS utility to delete the tape datasets as shown below. This also avoids the unnecessary delay in the execution of the job.

//STEP1 EXEC PGM=IDCAMS
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
DEL MY.TAPE.DSN
/*

VSAM buffering tips

Tuning Sequential Access

Default data buffers for KSDS is 2

one reserved for splits
#of I/O equal number of data CI’s that contain data

Determining Optimal Data Buffers for Input Data Set

Best performance is achieved when data component is read in full tracks

CI/Track=(PHYRECS/TRK) x (PHYREC-SIZE)

CISZD

PHYRECS/TRK = physical records per track - from LISTCAT

PHYREC-SIZE = physical record size - from LISTCAT

CISZD= data control interval size - from LISTCAT

Optimum value of BUFND is =CIs per track +1

Example:

From IDCAMS LISTCAT..

CISIZE--------------4096

PHYRECS/TRK-----------12

PHYREC-SIZE---------4096

CI/Track=12 x 4096 = 12

BUFND (for input dataset)=CI/TRK+1 = 13

BUFND (for output dataset)=CI/TRK+2 = 14

Random Access - Batch

Default index buffers for KSDS is 1

Best performance is achieved when enough buffers are allocated to keep all index CI’s in memory, plus one for the sequence set reads.

Index Buffers for Input Data Set

BUFNI=HURBAI - HURBAD + 1

CISZI CISZD X (CI/CA)

HURBAI = High Used RBA of index component - from LISTCAT

HURBAD = High Used RBA of data component - from LISTCAT

CI/CA = number of data CI in each data CA - from LISTCAT

CISZI= index control interval size - from LISTCAT

CISZD= data control interval size - from LISTCAT

Example:

From IDCAMS LISTCAT..

HI-U-RBA (index)-----------12288

CISIZE (data)--------------4096

HI-U-RBA (data)----------540672

CI/CA--------------------12

BUFNI = 12288 - 540672 + 1

1024 4096 X 12

BUFNI = 12 - 11 + 1 = 2

COBOL: Blocked and unblocked files

If the creating program lacks a file blocking statement the dataset is created with no record blocking (i.e. FIXED)!!

FD CRBREDL
BLOCK CONTAINS 0 RECORDS ---> If omitted causes BLKSIZE=F
LABEL RECORD IS STANDARD
RECORDING MODE IS F.
01 CRBREDL-REC PIC X(43).

From the IBM manual, "Enterprise COBOL for Z/OS"

"In a COBOL program, you can establish the size of a physical record with the BLOCK CONTAINS clause. If you do not use this clause, the compiler assumes that the records are NOT blocked. Blocking QSAM files on disk can enhance processing speed and minimize storage requirements."

	SPACE (cyls)	EXCPS (number of I/Os)	# Records	CLOCK TIME (minutes)
Unblocked (LRECL=43)	2588	4142000	1107944	149.2
Blocked at half-track (standard)	183	1061000	1250200	73.3
Savings	93% reduction	74% reduction	13% increase	51% reduction

Huge space and clock savings in spite of 13% increase in volume.

Monday, February 13, 2012

COBOL : Auto key generation

You might have come across situations in batch programs to auto generate keys.

Let us say we want to generate four byte keys in the following order

0001,0002,0003,…..9999,999A,……ZZZZ

The below program reads the last key generated and generates next key

WORKING-STORAGE SECTION.

01 REC1.

05 FILLER PIC X(36)

VALUE '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ'.

01 REC2 REDEFINES REC1.

05 CHAR PIC X(01) OCCURS 36 TIMES

INDEXED BY IX1, IX2, IX3, IX4.

01 LAST-KEY PIC X(04).

01 NEXT-KEY PIC X(04).

PROCEDURE DIVISION.

MOVE 'YYYY' TO LAST-KEY.

PERFORM VARYING IX1 FROM 1 BY 1

UNTIL CHAR(IX1) = LAST-KEY(1:1)

END-PERFORM

PERFORM VARYING IX2 FROM 1 BY 1

UNTIL CHAR(IX2) = LAST-KEY(2:1)

END-PERFORM

PERFORM VARYING IX3 FROM 1 BY 1

UNTIL CHAR(IX3) = LAST-KEY(3:1)

END-PERFORM

PERFORM VARYING IX4 FROM 1 BY 1

UNTIL CHAR(IX4) = LAST-KEY(4:1)

END-PERFORM

IF IX4 = 36

SET IX4 TO 1

IF IX3 = 36

SET IX3 TO 1

IF IX2 = 36

SET IX2 TO 1

IF IX1 = 36

SET IX1 TO 1

ELSE

SET IX1 UP BY 1

END-IF

ELSE

SET IX2 UP BY 1

END-IF

ELSE

SET IX3 UP BY 1

END-IF

ELSE

SET IX4 UP BY 1

END-IF

MOVE CHAR(IX1) TO NEXT-KEY(1:1)

MOVE CHAR(IX2) TO NEXT-KEY(2:1)

MOVE CHAR(IX3) TO NEXT-KEY(3:1)

MOVE CHAR(IX4) TO NEXT-KEY(4:1)

DISPLAY NEXT-KEY

GOBACK.

Wednesday, February 8, 2012

What is QA Hiperstation

Compuware Hiperstation is a suite of tools that streamlines the testing process and helps improve the quality of your applications. The Hiperstation tool suite offers these products:

•Hiperstation for VTAM provides the means for testing applications that use a 3270 user interface, or SNA LU0/LU2 communication protocols via unattended and interactive tools. It also provides an Automated Testing Vehicle (ATV) Manager and an auditing function for security monitoring.

•Hiperstation for Mainframe Servers includes support for testing applications using HTTP and HTTPS protocols. It includes SNA testing support and expands this support to test APPC/LU6.2 applications.

•Hiperstation for WebSphere MQ enables the testing of applications that use WebSphere MQ.

All of the Hiperstation products include the following functions:

•Record: Captures user sessions on a keystroke-by-keystroke or message-by-message basis. This is accomplished through a global record function for ALL components and interactively in the case of 3270 applications.

•Playback: Re-executes previously recorded sessions either online in interactive or non-stop mode, or in a batch job.

•Comparison: Compares the output of the current playback session with the recorded session.

Each of the components also has specific capabilities to aid testing in their respective environments. For advanced testing, Hiperstation incorporates IBM's REXX script language, allowing you to customize and enhance script creation, playback, and reporting.

Using QA Hiperstation to record a CICS session

This article explains how to record the CICS transactions that you execute in a CICS region in a dataset using QA Hiperstation.

Select option “1” for “Hiperstation for VTAM”

------------------------ Hiperstation - Product Menu --------------------------

Option ===> 1

0 Hiperstation Profiles Set user profiles

1 Hiperstation for VTAM VTAM Application Testing

2 Hiperstation for Mainframe Server SNA/APPC & HTTP Testing (Not licensed)

3 Hiperstation for WebSphere MQ WebSphere MQ Message Tes (Not licensed)

Profile ===>

Profile dataset ===>

Leave Profile blank for selection list

Leave Profile dataset blank to create new dataset

Leave both blank to run with no Profile

See Hiperstation frequently asked questions at:

http://frontline.compuware.com

Unpublished-rights Reserved Under the Copyright Laws of the United States .

Type LEGAL on the command line for Copyright/Trade Secret Notice information

Select option “1”

------------------------- Hiperstation - Main Menu --------------------------

Option ===> 1

Product Release: 07.08.00

1 Domain Traveler Record and Playback

2 Quick Play Select a Script and Go

3 Session Demo Demonstrate Online Applications

4 Global Recording System and Application Test Creation

5 Archive/Search Audit and Help Desk Functions

6 Script Processors Automatic Script Editing

7 Unattended Processing Setup Unattended Playback and Compare Jobs

8 File Manager File Manager

9 ATV Manager Automated Testing Vehicle (ATV) Manager

Type CICS region name as shown below

------------------------ Hiperstation * Domain Traveler -----------------------

Command ===>

Use this panel to connect to one of your site's domains. When

connected you can record your session or play back previous sessions.

Domain Destination . CICSTEST

Change session options (Enter "/")

Start = ISPF , Zoom = F23 , LUName = Default , Restore Keyboard

Logmode = D4A32782 , Model = 3-(32X80) , SNA = Yes , Queriable = Yes

Application Profiling(Off) , IMS = Y

Type command “ RECORD ON ” to record the transactions

ZOOM:F23 ------------------ HIPERSTATION ------------------------ LINE 1 OF 24

Command ===> record on Scroll ===> PAGE

Record OFF Play OFF Journal OFF Compare Log OFF autoDoc OFF

Signon to CICS APPLID CICSTEST

WELCOME TO CICS/TS 4.1.0 REGION CICSTEST

Type your userid and password, then press ENTER:

Userid . . . . Groupid . . .

Password . . .

Language . . .

New Password . . .

In the ISPF 3.2 screen allocate a PDS as shown below.

Menu RefList Utilities Help

ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss

Allocate New Data Set

Command ===>

More: +

Data Set Name . . . : TSUXXXX.QAH

Management class . . . (Blank for default management class)

Storage class . . . . (Blank for default storage class)

Volume serial . . . . (Blank for system default volume) **

Device type . . . . . (Generic unit or device address) **

Data class . . . . . . (Blank for default data class)

Space units . . . . . CYLINDER (BLKS, TRKS, CYLS, KB, MB, BYTES

or RECORDS)

Average record unit (M, K, or U)

Primary quantity . . 2 (In above units)

Secondary quantity 2 (In above units)

Directory blocks . . 0 (Zero for sequential data set) *

Record format . . . . VB

Record length . . . . 256

Block size . . . . .

Data set name type LIBRARY (LIBRARY, HFS, PDS, LARGE, BASIC, *

EXTREQ, EXTPREF or blank)

Extended Attributes (NO, OPT or blank)

Type the PDS allocated above with a member as shown below

------------------------ Hiperstation * Recording Setup -----------------------

Command ===>

Recording File Name:

Project . . . .

Group . . . . .

Type . . . . .

Member . . . . (Blank or pattern for member selection list)

Other Dsn . . . 'TSUXXXX.QAH(TEST)'

Description . .

Recording Options:

Enter "/" to select option

Replace Like Member(s)

/ Format Recording

Record Inputs Only

Stop Recording

/ Script Recovery

Input fields in (row,column) format

File Manager

Press ENTER to begin recording, END to cancel setup.

Below screen shows that Hiperstation is ready to record your transaction

ZOOM:F23 ------------------ HIPERSTATION --------------- RECORDING IN PROGRESS

Command ===> Scroll ===> PAGE

Recording TEST Play OFF Journal OFF Compare Log OFF autoDoc OFF

Signon to CICS APPLID CICSTEST

WELCOME TO CICS/TS 4.1.0 REGION CICSTEST

Type your userid and password, then press ENTER:

Userid . . . . Groupid . . .

Password . . .

Language . . .

New Password . . .

Use Shift+PF11 to toggle between the Hiperstation menu and the region. Pressing Shift+PF11 key in the above screen, shows the below CICS screen in full screen mode.

Signon to CICS APPLID CICSTEST

WELCOME TO CICS/TS 4.1.0 REGION CICSTEST

Type your userid and password, then press ENTER:

Userid . . . . TSUXXXX Groupid . . .

Password . . .

Language . . .

New Password . . .

DFHCE3520 Please type your userid.

F3=Exit

Completed the above sign on screen and entered “CMAC” transaction.

CMAC

DFHCE3549 Sign-on is complete (Language ENU).

Type “ASRA” to see the explanation

DFHCMC01 Display On-line Messages and Codes

Type the required message identifier, then press Enter.

Component ID. . . . (for example, TC for Terminal Control

FC for File Control, etc.)

This field is required for messages in the

form DFHxxyyyy, where xx is the Component ID.

Message Number. . . ASRA (for example, 1060, 5718, or Abend Code

such as ASRA, etc.)

F3=Exit to CICS

ASRA

EXPLANATION: The task has terminated abnormally because

of a program check.

SYSTEM ACTION: The task is abnormally terminated and CICS

issues either message DFHAP0001 or DFHSR0001. Message

DFHSR0622 may also be issued.

USER RESPONSE: Refer to the description of the associated

message or messages to determine and correct the cause of

the program check.

MODULE: DFHSRP

F3=Cancel

Press clear key and then Shift+PF11 key to go back to Hiperstation and type “RECORD OFF” to stop the recording.

ZOOM:F23 ------------------ HIPERSTATION ------------------------ LINE 1 OF 24

Command ===> RECORD OFF Scroll ===> PAGE

Recording TEST Play OFF Journal OFF Compare Log OFF autoDoc OFF

The blow screen shows that recording has stopped

ZOOM:F23 ------------------ HIPERSTATION ------------------- RECORDING STOPPED

Command ===> Scroll ===> PAGE

Record OFF Play OFF Journal OFF Compare Log OFF autoDoc OFF

Type “CANCEL” to disconnect the CICS session

ZOOM:F23 ------------------ HIPERSTATION ------------------- RECORDING STOPPED

Command ===> CANCEL Scroll ===> PAGE

Record OFF Play OFF Journal OFF Compare Log OFF autoDoc OFF

Browsing the dataset shows that CICS transaction has been recorded in the dataset.

Menu Utilities Compilers Help

sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss

BROWSE TSUXXXX.QAH(TEST) - 00.00 Line 00000000 Col 001 080

Command ===> Scroll ===> CSR

********************************* Top of Data **********************************

************************************************************************

* CREATED BY USER: TSUXXXX TPF: CICSTEST TIME: 20:39 DATE: 02/08/12 *

* DESC: *

************************************************************************

* LU: UHG02Q01 TPF: CICSTEST LOGMODE: D4A32782 *

************************************************************************

<VERSION>7

<IMSUNLOK>Y

<OUTPUT>0000001 (24,080)

<RESPONSE>00.00.000

<S01>............................Signon to CICS ......................APPLID.CIC

<S02>

<S03>.WELCOME TO CICS/TS 4.1.0 REGION CICSTEST

<S04>.

<S05>.

<S06>.

<S07>

<S08>.Type your userid and password, then press ENTER:

<S09>